Tablet Printing Surface Modification for Ink Adhesion
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Solution Overview
Problem
Conventional inkjet printing methods for tablets suffer from poor adhesion and spread of ink due to surface conditions, leading to distorted images and reduced recognizability, especially on coated tablets, and there is a need for techniques that can print detailed images and prevent forgery.
Innovation Solution
A tablet printing apparatus that uses a combination of ultraviolet and infrared rays to modify the surface of tablets, creating a recessed shape for inkjet printing, which improves ink adhesion and prevents ink spread, and includes a spatial light modulator to control the pattern of irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional inkjet printing is used on tablet surfaces, then printing can be performed, but ink adhesion is poor and ink spreads causing distorted images
Solution Approach 1:
The patent applies preliminary action by treating the tablet surface with ultraviolet or infrared rays before inkjet printing. This pre-treatment modifies the surface properties to improve ink adhesion and prevent ink spread, ensuring high print quality without distortion.
Solution Approach 2:
The patent changes the physical state of the tablet surface through exposure to ultraviolet or infrared rays. This parameter change modifies the surface energy and wettability, enabling better ink adhesion and preventing ink spread while maintaining clear image contours.
2Manufacturing precision
If contact printing methods are used, then printing can be performed, but tablets are damaged due to pressure
Solution Approach 1:
The patent replaces the mechanical contact printing system with a non-contact inkjet printing system. This substitution eliminates the mechanical pressure that damages tablets while maintaining high print quality through precise ink deposition controlled by digital imaging.
Solution Approach 2:
The patent introduces an intermediary process of surface treatment with ultraviolet or infrared rays between the printing process and the tablet surface. This intermediary treatment prepares the surface for ink adhesion without requiring mechanical contact, thus preserving tablet integrity.
3Productivity
If conventional inkjet printing is used on coated tablets, then printing can be performed, but ink spread causes poorly defined contours
Solution Approach 1:
The patent applies preliminary surface treatment with ultraviolet or infrared rays to coated tablets before inkjet printing. This pre-treatment creates optimal surface conditions that prevent ink spread, ensuring well-defined contours and high manufacturing precision while maintaining printing capability.
Solution Approach 2:
The patent changes the surface parameters of coated tablets through exposure to ultraviolet or infrared rays. This modification of surface energy and wettability parameters prevents ink spread on the coated surface, achieving sharp contours and detailed images without sacrificing printing productivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus achieves well-defined contours and improved adhesion of ink on tablet surfaces, reducing the risk of ink spreading and enhancing the clarity of printed images, including logos and codes, while preventing forgery.
Implementation Method 1
an exposure part that applies at least one of ultraviolet rays and infrared rays to a surface of a tablet that is conveyed by the conveying mechanism
Implementation Method 2
an exposure part that applies at least one of ultraviolet rays and infrared rays to a surface of a tablet that is conveyed by the conveying mechanism
Implementation Method 3
an inkjet head that ejects ink toward a surface of a tablet that has passed through the exposure part
Data Source
AI summary
A tablet printing apparatus first applies either ultraviolet rays or infrared rays to surfaces of tablets that are being conveyed. The ultraviolet or infrared rays are applied to at least a contour portion of a target area where a print image is to be formed. In the case of applying ultraviolet rays, the surface of the contour portion is roughened, and the angle of contact with ink is reduced. In the case of applying infrared rays, the contour portion is etched into a recessed shape. Thereafter, ink is ejected inside the contour portion. This configuration suppresses the spread of the ejected ink to the outside of the target area. As a result, the print image has a well-defined contour.